Groowe Groowe BETA / Newsroom
⏱ News is delayed by 15 minutes. Sign in for real-time access. Sign in

Form 8-K

sec.gov

8-K — CALIFORNIA WATER SERVICE GROUP

Accession: 0001104659-26-064607

Filed: 2026-05-20

Period: 2026-05-20

CIK: 0001035201

SIC: 4941 (WATER SUPPLY)

Item: Regulation FD Disclosure

Item: Financial Statements and Exhibits

Documents

8-K — tm2615262d1_8k.htm (Primary)

EX-99.1 — EXHIBIT 99.1 (tm2615262d1_ex99-1.htm)

GRAPHIC (tm2615262d1_ex99-1img01.jpg)

GRAPHIC (tm2615262d1_ex99-1img02.jpg)

XML — IDEA: XBRL DOCUMENT (R1.htm)

8-K — FORM 8-K

8-K (Primary)

Filename: tm2615262d1_8k.htm · Sequence: 1

false

0001035201

0001035201

2026-05-20

2026-05-20

iso4217:USD

xbrli:shares

iso4217:USD

xbrli:shares

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

Current Report Pursuant to Section 13

or 15(d) of

The Securities Exchange Act of 1934

Date of Report (date of earliest event

reported): May 20, 2026

CALIFORNIA WATER SERVICE GROUP

(Exact name of Registrant as Specified in its

Charter)

Delaware

(State or other jurisdiction

of incorporation)

1-13883

(Commission file number)

77-0448994

(I.R.S. Employer

Identification Number)

1720 North First Street

San Jose, California

(Address of principal executive offices)

95112

(Zip Code)

(408) 367-8200

(Registrant’s telephone number, including

area code)

N/A

(Former name or former address, if changed

since last report)

Check the appropriate box below if the Form 8-K filing

is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

¨

Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨

Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨

Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act

(17 CFR 240.14d-2(b))

¨

Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act

(17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of

the Act:

Title of each class

Trading Symbol(s)

Name of each exchange on which registered

Common Shares, par value $0.01

CWT

New York Stock Exchange

Indicate by check mark whether the registrant is an emerging

growth company as defined by Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of

the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ¨

If an emerging growth

company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or

revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

Item 7.01.

Regulation FD Disclosure

On May 20, 2026, California Water Service Group (Group)

issued a press release (a copy of which is attached hereto as Exhibit 99.1 and incorporated herein by reference) announcing the promotion

of Tamara S. Johnson to Vice President, California Operations and Gregory D. Shimansky to Vice President, Rates and Regulatory Affairs

effective July 1, 2026.

Item 9.01.

Financial Statements and Exhibits.

We hereby file the following exhibit with this report:

Exhibit No.

Description

99.1

Press Release issued May 20, 2026

104

Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities

Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

CALIFORNIA WATER SERVICE GROUP

Date: May 20, 2026

By:

/s/ Martin A. Kropelnicki

Name:

Martin A. Kropelnicki

Title:

Chairman, President and Chief Executive Officer

EX-99.1 — EXHIBIT 99.1

EX-99.1

Filename: tm2615262d1_ex99-1.htm · Sequence: 2

Exhibit 99.1

DATE:

May 20, 2026

CONTACT:

Shannon Dean, (408) 367-8243

For

Immediate Release

California

Water Service Group Promotes Tamara S. Johnson to

Vice President, California Operations and Gregory D. Shimansky to

Vice President, Rates

and Regulatory Affairs.

SAN JOSE, Calif., May

20, 2026 - At its meeting today, the California Water Service Group (CWT: NYSE) Board of Directors unanimously approved the promotions

of Tamara S. Johnson to Vice President, California Operations, and Gregory D. Shimansky to Vice President, Rates and Regulatory Affairs,

effective July 1, 2026.

Prior to joining the executive team,

Johnson served as Director of Field Operations, Southern California Region. She brings 40 years of public water utility experience to

the position, having started her career at California Water Service, Group's largest subsidiary, in 1985. Johnson holds a Master of Business

Administration from California State University, Monterey Bay, a Bachelor of Science in Business Administration from the University of

La Verne, as well as a Water Treatment Operator License Grade 3 and a Water Distribution License Grade 5 from the State of California.

The Vice President, California Operations role is newly created.

"This

new position reflects our company's growth and the increasing complexity of water utility operations. Tammy is not only a water

utility operations expert, she's also an accomplished professional with a track record of getting things done. It's truly a pleasure

to welcome to the officer team someone who has dedicated her entire career to the company," said Chairman and Chief Executive

Officer Martin A. Kropelnicki.

Shimansky joined California Water

Service Group in 2024 as a director focused on rates and regulatory affairs outside of California. Before joining the Group, he served

as Rates and Regulatory Affairs Director at Indiana American Water and General Rate Case Program Manager at San Diego Gas and Electric.

He holds a Master of Science in Management from Purdue University and a Bachelor of Arts in Economics from the University of California,

Los Angeles. He succeeds Greg A. Milleman, who is retiring after a distinguished 10-year career at Group.

"Greg is results-oriented, and

he has done a tremendous job for us thus far. I believe he will be a real asset to the Company as we continue to pursue regulatory mechanisms

and rate designs that help keep our rates affordable for customers while allowing us to make the investments in water system infrastructure

that help keep our water service safe and reliable," Kropelnicki said.

About California

Water Service Group

Group is the parent company of regulated

utilities California Water Service, Hawaii Water Service, New Mexico Water Service, and Washington Water Service, as well as Texas Water

Service, a utility holding company. Together, these companies provide regulated and non-regulated water and wastewater service to more

than 2.1 million people in California, Hawaii, New Mexico, Washington, and Texas. Group’s common stock trades on the New York Stock

Exchange under the symbol “CWT.” Additional information is available online at www.calwatergroup.com.

#

GRAPHIC

GRAPHIC

Filename: tm2615262d1_ex99-1img01.jpg · Sequence: 6

Binary file (22378 bytes)

Download tm2615262d1_ex99-1img01.jpg

GRAPHIC

GRAPHIC

Filename: tm2615262d1_ex99-1img02.jpg · Sequence: 7

Binary file (7390 bytes)

Download tm2615262d1_ex99-1img02.jpg

XML — IDEA: XBRL DOCUMENT

XML

Filename: R1.htm · Sequence: 9

v3.26.1

Cover

May 20, 2026

Cover [Abstract]

Document Type

8-K

Amendment Flag

false

Document Period End Date

May 20, 2026

Entity File Number

1-13883

Entity Registrant Name

CALIFORNIA WATER SERVICE GROUP

Entity Central Index Key

0001035201

Entity Tax Identification Number

77-0448994

Entity Incorporation, State or Country Code

DE

Entity Address, Address Line One

1720 North First Street

Entity Address, City or Town

San Jose

Entity Address, State or Province

CA

Entity Address, Postal Zip Code

95112

City Area Code

408

Local Phone Number

367-8200

Written Communications

false

Soliciting Material

false

Pre-commencement Tender Offer

false

Pre-commencement Issuer Tender Offer

false

Title of 12(b) Security

Common Shares, par value $0.01

Trading Symbol

CWT

Security Exchange Name

NYSE

Entity Emerging Growth Company

false

X

- Definition

Boolean flag that is true when the XBRL content amends previously-filed or accepted submission.

+ References

No definition available.

+ Details

Name:

dei_AmendmentFlag

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

na

Period Type:

duration

X

- Definition

Area code of city

+ References

No definition available.

+ Details

Name:

dei_CityAreaCode

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

na

Period Type:

duration

X

- Definition

Cover page.

+ References

No definition available.

+ Details

Name:

dei_CoverAbstract

Namespace Prefix:

dei_

Data Type:

xbrli:stringItemType

Balance Type:

na

Period Type:

duration

X

- Definition

For the EDGAR submission types of Form 8-K: the date of the report, the date of the earliest event reported; for the EDGAR submission types of Form N-1A: the filing date; for all other submission types: the end of the reporting or transition period. The format of the date is YYYY-MM-DD.

+ References

No definition available.

+ Details

Name:

dei_DocumentPeriodEndDate

Namespace Prefix:

dei_

Data Type:

xbrli:dateItemType

Balance Type:

na

Period Type:

duration

X

- Definition

The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word 'Other'.

+ References

No definition available.

+ Details

Name:

dei_DocumentType

Namespace Prefix:

dei_

Data Type:

dei:submissionTypeItemType

Balance Type:

na

Period Type:

duration

X

- Definition

Address Line 1 such as Attn, Building Name, Street Name

+ References

No definition available.

+ Details

Name:

dei_EntityAddressAddressLine1

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

na

Period Type:

duration

X

- Definition

Name of the City or Town

+ References

No definition available.

+ Details

Name:

dei_EntityAddressCityOrTown

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

na

Period Type:

duration

X

- Definition

Code for the postal or zip code

+ References

No definition available.

+ Details

Name:

dei_EntityAddressPostalZipCode

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

na

Period Type:

duration

X

- Definition

Name of the state or province.

+ References

No definition available.

+ Details

Name:

dei_EntityAddressStateOrProvince

Namespace Prefix:

dei_

Data Type:

dei:stateOrProvinceItemType

Balance Type:

na

Period Type:

duration

X

- Definition

A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

+ Details

Name:

dei_EntityCentralIndexKey

Namespace Prefix:

dei_

Data Type:

dei:centralIndexKeyItemType

Balance Type:

na

Period Type:

duration

X

- Definition

Indicate if registrant meets the emerging growth company criteria.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

+ Details

Name:

dei_EntityEmergingGrowthCompany

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

na

Period Type:

duration

X

- Definition

Commission file number. The field allows up to 17 characters. The prefix may contain 1-3 digits, the sequence number may contain 1-8 digits, the optional suffix may contain 1-4 characters, and the fields are separated with a hyphen.

+ References

No definition available.

+ Details

Name:

dei_EntityFileNumber

Namespace Prefix:

dei_

Data Type:

dei:fileNumberItemType

Balance Type:

na

Period Type:

duration

X

- Definition

Two-character EDGAR code representing the state or country of incorporation.

+ References

No definition available.

+ Details

Name:

dei_EntityIncorporationStateCountryCode

Namespace Prefix:

dei_

Data Type:

dei:edgarStateCountryItemType

Balance Type:

na

Period Type:

duration

X

- Definition

The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

+ Details

Name:

dei_EntityRegistrantName

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

na

Period Type:

duration

X

- Definition

The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b-2

+ Details

Name:

dei_EntityTaxIdentificationNumber

Namespace Prefix:

dei_

Data Type:

dei:employerIdItemType

Balance Type:

na

Period Type:

duration

X

- Definition

Local phone number for entity.

+ References

No definition available.

+ Details

Name:

dei_LocalPhoneNumber

Namespace Prefix:

dei_

Data Type:

xbrli:normalizedStringItemType

Balance Type:

na

Period Type:

duration

X

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 13e

-Subsection 4c

+ Details

Name:

dei_PreCommencementIssuerTenderOffer

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

na

Period Type:

duration

X

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 14d

-Subsection 2b

+ Details

Name:

dei_PreCommencementTenderOffer

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

na

Period Type:

duration

X

- Definition

Title of a 12(b) registered security.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection b

+ Details

Name:

dei_Security12bTitle

Namespace Prefix:

dei_

Data Type:

dei:securityTitleItemType

Balance Type:

na

Period Type:

duration

X

- Definition

Name of the Exchange on which a security is registered.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 12

-Subsection d1-1

+ Details

Name:

dei_SecurityExchangeName

Namespace Prefix:

dei_

Data Type:

dei:edgarExchangeCodeItemType

Balance Type:

na

Period Type:

duration

X

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as soliciting material pursuant to Rule 14a-12 under the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Exchange Act

-Number 240

-Section 14a

-Subsection 12

+ Details

Name:

dei_SolicitingMaterial

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

na

Period Type:

duration

X

- Definition

Trading symbol of an instrument as listed on an exchange.

+ References

No definition available.

+ Details

Name:

dei_TradingSymbol

Namespace Prefix:

dei_

Data Type:

dei:tradingSymbolItemType

Balance Type:

na

Period Type:

duration

X

- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as written communications pursuant to Rule 425 under the Securities Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Securities Act

-Number 230

-Section 425

+ Details

Name:

dei_WrittenCommunications

Namespace Prefix:

dei_

Data Type:

xbrli:booleanItemType

Balance Type:

na

Period Type:

duration